Radio-frequency identification (RFID) is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to objects. The tags contain electronically stored information. An RFID system identifies a tag without establishing a mechanical or optical contact with the RFID tag. For different types of RFID tags in different situations, different types of RFID reader systems have been designed to be used. Hence a user may need to purchase and use multiple RFID reader systems to satisfy specific application requirements.